JPS60209063A - Measurement of density of knitted fabric - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the density of woven and knitted fabrics.

Conventionally, various methods have been used to measure the density, which is one of the morphological characteristics of woven or knitted fabrics, that is, the number of threads or stitches in the warp and weft directions per unit length of the fabric. A method in which the knitted fabric is loosened and the threads are taken out one by one and measured based on the number of threads; a method in which the unit field of view is magnified using a lens system and the density is measured from the enlarged image; Using a transparent plate with vertical stripes carved at varying intervals, the densitometer is superimposed on the fabric surface with different orientations in the vertical and horizontal directions, and the moire pattern detected in each case is measured. There are ways to measure density.

Among these methods, the method of unraveling the woven fabric and measuring the number of threads is a reliable method, but it takes time to produce results and is completely destructive because it involves cutting out a part of the fabric and measuring it. It is an inspection. Further, although the method of enlarging and measuring with a lens system is a non-destructive testing method, it is essentially the same as the method of loosening and measuring the fabric, and the work itself is detailed and complicated. On the other hand, the method using a densitometer is a nondestructive testing method similar to the method using the lens system described above, and moreover, the measurement can be performed in a much shorter time than the above two methods.

However, all of these methods involve human intervention, which inevitably causes various measurement errors, and it is impossible to measure automatically, and furthermore, the measurement results cannot be transferred to other devices in real time. Nor can it be used as a source of information for input into the .

In view of the above, the present invention is a method for automatically and highly accurately measuring the density of woven or knitted fabrics without human intervention, and in particular, the present invention provides a method for automatically and highly accurately measuring the density of woven or knitted fabrics, and in particular, by measuring images and fundamental waveforms of woven or knitted fabrics. The purpose of this paper is to provide a method for measuring density using a simple process of correlation processing.

In order to achieve such an objective, the density measurement method of the present invention includes the following steps:
By capturing an image of the woven or knitted fabric to be measured using an imaging device and converting it into an electrical signal, fabric image information containing information about the density of the delicate fabric is obtained, and a steady waveform in which the frequency is sequentially changed slightly is used. An information processing device that generates waveform information performs correlation processing between the fabric image information and basic waveform information, and calculates the density of the woven fabric from the frequency corresponding to the maximum correlation value obtained by the processing. This is a characteristic feature.

The method of the present invention will be explained in more detail below with reference to the drawings.

FIG. 1 shows the configuration of an apparatus used to implement the present invention,
1 is a woven or knitted fabric to be measured; 2 is an imaging device including an optical system 3 with a zooming mechanism and an imaging tube 4; 5 is an interface; 8 is an information processing device consisting of an electronic computer;
indicates a display device.

When measuring the density of a woven or knitted fabric, the above-mentioned apparatus uses an optical system 3 to obtain a fabric image (Fig.
A field of view and magnification are determined by a zooming mechanism, and an image is captured by an image pickup tube 4 such as a vidicon camera or a COD camera, where it is converted into fabric image information as an electrical signal. This fabric image information has information regarding the density in the warp and lateral directions of the woven fabric obtained from the reflection or transmission characteristics of the surface of the woven fabric, and is sent to the information processing device He via the interface 5. , is stored in its internal storage unit.

FIG. 2B shows fabric image information about the weaving, knitting, and reflection or transmission characteristics of the surface of the fabric stored in the storage unit, which is obtained by scanning along a number of scanning lines in the warp direction.
Figure E shows information obtained when scanning is performed along a number of scanning lines in the weft direction.

The information processing device 8, as shown in FIG. 2 C and F,
Electrically generates a steady waveform with slightly different frequencies,
Using these as basic waveform information, correlation processing is sequentially performed with fabric image information in the warp direction and weft direction in the storage section, and the correlation value is outputted to the display device 7 in relation to the frequency.

The above correlation processing is performed on the fabric density information on appropriately sampled scanning lines or the fabric density information on a certain number of scanning lines and the above basic waveform information, and the correlation information in the vertical and horizontal directions obtained thereby is As illustrated in Figure 1 and G, when frequency changes are plotted on the vertical axis and correlation values are plotted on the horizontal axis, the frequency corresponding to the maximum correlation value is displayed as being proportional to the density of the fabric. Therefore, the information processing device 6 calculates the densities of the woven fljIl in both the vertical and horizontal directions from the frequency corresponding to the maximum correlation value, and displays these densities on the display device 7. Naturally, when calculating the density, correction is performed using the magnification ratio of the zooming mechanism of the optical system 3.

FIG. 2 visually represents the information processing process performed in the information processing device 8. As shown in FIG. That is, A, B, C, D, and A in the same figure.

E, F, and G indicate processing steps for measuring the density in the warp direction and the width direction of the woven fabric 1, respectively, and fabric density information (B, E) is obtained from the woven fabric image (A). , correlation information (D, G) is obtained by correlating these information with the basic waveform information (C, F).

Note that in the density measurement method described above, all the fabric image data within the field of view can be stored in the storage unit of the information processing device and processed, but the image data and frequency of one scanning line L in the imaging device can be sequentially processed. By calculating the correlation with the changed stationary waveform, storing the correlation value, and calculating the maximum value, it is possible to further speed up information processing.

Further, the information processing by the information processing device 6 can be performed by an electronic computer, but it can also be performed by a combination of electronic circuits configured to perform the same function.

As is clear from the detailed description above, according to the present invention, density measurements of woven or knitted fabrics can be performed automatically, non-contact, at high speed, and with high accuracy without damaging the fabric.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an apparatus used to carry out the present invention, and FIG. 2 is an explanatory diagram showing an information processing process of an image of a woven or knitted fabric. 1. Woven or knitted fabric, 2. Imaging device, 6. Dispute information processing device. designated agent

Claims (1)

[Claims] ■By capturing an image of the #lti knitted fabric to be measured using an imaging device and converting it into an electrical signal, fabric image information containing information about the density of the woven fabric is obtained, and a steady waveform with a frequency that is successively changed slightly. In an information processing device that generates basic waveform information, correlation processing is performed between the fabric image information and basic waveform information, and the density of the woven fabric is calculated from the frequency corresponding to the maximum correlation value obtained by the processing. A method for measuring the density of woven or knitted fabrics.